JPH0539822U - Quick return mechanism of piston for hydraulic tools - Google Patents

Abstract

(57) [Abstract] [Purpose] In a hydraulic tool equipped with a so-called two-stage piston mechanism on the output side, the output piston can be quickly returned by a simple operation, and
To obtain a piston quick return mechanism with little damage and good durability. [Structure] A relief valve between a cylinder and an oil tank and a return valve for hydraulic oil are provided in separate oil passages, and a bottom portion of a small cylinder formed in a state of being opened to a base end face side in an output piston and the above-mentioned An unload valve is provided in an oil passage between the bases of the cylinders, and the unload valve and the return valve are configured so that they can be simultaneously and externally opened by operation of a return mechanism such as a return lever.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an actuation mechanism of a hydraulic tool used for cutting and connecting electric wires, etc., and more particularly to a piston quick return mechanism of a manual hydraulic tool having a rapid feed piston.

[0002]

[Prior Art]

 Conventionally, as a manual hydraulic tool provided with a rapid-feed mechanism of a piston, there is one as shown in FIG. In this manual hydraulic tool B, an oil tank 52 is provided at the base end portion of the tool body 51, and a cylinder 53 formed at the tip end portion of the tool body 51 has an output piston urged to the base end side by a spring 54. 55 is housed. In this output piston 55, a small cylinder 56 is formed which opens to the base end side, and a small diameter rapid feed piston 58 having an oil passage 57 penetrating the small cylinder 56 and one end of which is attached to the tool body 51 side. It is in a housed state.

A fast-forwarding oil chamber 59 is formed in the tool body 51 portion in contact with the base end portion of the fast-forwarding piston 58, and working oil sucked from the oil tank 52 is supplied by a pump mechanism (not shown). In addition, an unload valve 61 is provided in an oil passage 60 which communicates from the rapid feed oil chamber 59 to the base of the cylinder 53.

Therefore, the hydraulic oil can be supplied to the small cylinder 56 in the output piston 55 via the oil passage 57 of the fast-forwarding piston 58 to fast-forward the output piston 55, and the output piston 55 receives the load. When the pressure of the hydraulic oil rises and exceeds a predetermined pressure, the unload valve 61 is opened, the hydraulic oil is supplied to the base of the cylinder 53, and the output piston 55 can be operated. ing.

Further, as a mechanism for returning hydraulic oil, a return valve 63 which also functions as a relief valve is provided in an oil passage 62 which communicates between the rapid-feed oil chamber 59 and the oil tank 52, and a base portion of the cylinder 53 A check valve 64 is provided between the return valve 63 and the return valve 63 so that the return valve 63 can be opened by an external operation of the return lever 65 against the urging force of an internal spring. After the work is completed, the return lever 65 is pushed to return the internal hydraulic oil to the oil tank 52, and the output piston 55 can be returned to the original position.

FIG. 8 shows another conventional example of a manual hydraulic tool having a fast-forward piston mechanism. The piston rapid feed mechanism of the manual hydraulic tool C is equipped with a ram 73 formed in two stages of large and small diameters, which is inserted into a two-stage ram chamber 72 formed of a large diameter chamber and a small diameter chamber formed in the tool body 71. By swinging the attached pressure handle 74, the working oil is sucked from the oil tank 75 and supplied to the cylinder 76, and the output piston 77 accommodated in the cylinder 76 is moved.

That is, the large-diameter plunger portion 73a sends a large amount of hydraulic oil to fast-forward the output piston 77, and when a load is generated on the output piston 77, high pressure is applied to the small-diameter plunger portion 73b to perform work. It was done like this.

In this manual hydraulic tool C, a relief valve 79 and a return valve 80 that opens by an external force operation are provided in an oil passage 78 that communicates between the base of the cylinder 76 and the oil tank 75. The overpressure is removed during the work, and the output piston 77 is returned by returning the hydraulic oil after the work is completed.

As described above, as a rapid traverse mechanism for the piston in such a manual hydraulic tool, a system in which the output side piston is configured in two stages and a system in which the oil feeding side pump ram is formed in two stages However, the rapid feed speed is overwhelmingly higher in the system with a two-stage piston, and this system is used predominantly.

[0010]

[Problems to be solved by the device]

 However, in the hydraulic tool using the two-stage piston type rapid-feed mechanism, the relief circuit is usually simplified to avoid complicating the structure because it is necessary to withstand high output. The valve is configured to double as a return valve.

Therefore, the choke portion of the relief valve is a bottleneck in the hydraulic oil return circuit. In other words, the relief valve requires a spring force according to the cross-sectional area of the pressure receiving surface in terms of its function, so that the load on the storage spring is reduced, the durability of the parts is increased, and the operability of the return lever is improved. The hole diameter of the surface is made as small as possible to form a choke part with a small diameter.When such a relief valve is also used as a return valve, the choke part becomes a bottleneck when the hydraulic oil returns, so the piston It was slow to return, and it was a cause of hindering the efficiency of work.

Further, since such a relief valve is used as a return valve, the valve seat precisely finished to prevent oil leakage is significantly worn and damaged, and the durability of the hydraulic tool is reduced. It was also a cause for

Further, because of the relief pressure setting spring force in the relief valve, a high lever pressing force is always required when the return valve is opened, and there is a problem in operability.

In view of the above situation, the present invention is capable of fast-forwarding the piston and fast-returning the piston, which is excellent in workability, is easy to operate, and has a high durability. The purpose is to provide.

[0015]

[Means for Solving the Problems]

 In order to achieve the above object, the present invention provides an oil tank attached to the base end portion of a tool body, a cylinder formed at the tip end portion of the tool body, and a base end side housed in the cylinder and provided with a spring. Between the oil tank and the base of the cylinder, and an output piston that is biased to the cylinder, a fast-forward piston that has an oil passage inside and is housed in a small cylinder that is formed in the output piston. Return valve provided in the oil passage, an unload valve provided in the oil passage that communicates between the bottom of the small cylinder and the base of the cylinder, and hydraulic oil in the oil tank is sucked to suck the working oil of the small cylinder. A manual hydraulic tool equipped with a pump mechanism for pumping to the bottom, wherein a return mechanism for simultaneously opening the return valve and the unload valve from the outside is provided, and a space between the oil tank and the base of the cylinder is provided. There is provided a piston rewind mechanism of the hydraulic tool which is interposed a relief valve is newly provided an oil passage.

[0016]

[Action]

 When the pump mechanism is manually operated, the hydraulic oil in the oil tank is pumped to the bottom of the small cylinder, and the output piston can be pushed from the inside for fast forwarding. If the output piston that has been fast-forwarded stops after receiving the load and continues to send hydraulic oil, the hydraulic pressure will rise without waiting and the unload valve will open at the specified hydraulic pressure. Pressurized hydraulic oil is supplied, and the output piston moves forward with a high output to perform the required work.

During operation, if the hydraulic pressure of the hydraulic oil rises above a predetermined pressure, the relief valve will open, so the hydraulic oil at the base of the cylinder can be released directly to the oil tank and held below the predetermined pressure. it can.

When the pump operation is stopped due to the end of the work, the unload valve is closed, but when the return mechanism is manually operated, the unload valve is opened, and at the same time, the return valve is opened and the small cylinder bottom portion is opened. Since the opening between the oil tank and the base of the output piston and the oil tank opens, the hydraulic oil in the cylinder rapidly returns the hydraulic oil at the bottom of the small cylinder and the hydraulic oil at the base of the cylinder to the oil tank. It is quickly returned to the original position.

[0019]

【Example】

 The quick return mechanism of the hydraulic tool according to the present invention will be described below with reference to the accompanying drawings showing an embodiment. 1 is a side sectional view of a hydraulic tool having a quick return mechanism of the present invention, FIG. 2 is a sectional view taken along line II-II of FIG. 1, and FIG. 3 is a sectional view taken along line III-III of FIG. 4 is a sectional view taken along line IV-IV of FIG. 3, FIG. 5 is a sectional view taken along line VV of FIG. 3, and FIG. 6 is a hydraulic circuit diagram of the hydraulic tool of FIG.

As shown in FIG. 1 and FIG. 2, the hydraulic tool A according to the present invention is a hydraulic tool for manual crimping used in the end treatment of electric wires and the like. A grip portion 3 is attached so as to hold the tank 2.

At the tip of the tool body 1, a bottomed cylinder 4 that opens in the tip direction is formed, and an output piston 6 that is biased toward the base end side by a spring 5 is housed inside and a spacer 7 is provided. The cap 8 is attached. The tip portion of the rod 6a of the output piston 6 is projected to the outside of the tool body 1, and a crimping punch 9 is detachably and replaceably attached to the tip portion of the rod 6a, and the outer peripheral surface of the tip portion of the tool body 1 is attached. , The die holder 11 is attached via the head 10 by screwing means, and the die holder 11 holds the crimping die 12, and the crimping punch 9 advances and retreats according to the output piston 6 to crimp the crimping object 13 such as an electric wire. You can do it.

The output piston 6 is formed with a small cylinder 14 having a bottom that opens to the base end side along the central axis, and the fast-forwarding piston 15 fitted into this small cylinder 14 has its base end screwed. It is attached to the tool body 1 in a state of being inserted, and the rapid feed piston 15 is provided with a small diameter oil passage 16 penetrating the central shaft portion.

A small-body rapid-feed oil chamber 17 is formed in the tool body 1 portion in contact with the base end of the rapid-feed piston 15. Further, a ram chamber 19 formed as a pump mechanism 18 at the center of the side of the tool body 1, a ram 20 fitted into the ram chamber 19 and having one end protruding outside the tool body 1, and a protrusion of the ram 20. The hydraulic oil from the oil tank 2 sucked by the pump mechanism 18 is supplied to the fast-forward oil chamber 17, and further passes through the oil passage 16. And is supplied to the bottom portion 14a of the small cylinder 14.

That is, the oil passage 22 from the ram chamber 19 is branched into an oil passage 23 to the oil tank 2 and an oil passage 24 to the fast-forwarding oil chamber 17, and a check valve is provided in each of the oil passages 23 and 24. 25 and 26 are interposed, and by the swinging operation of the pressurizing handle 21 of the pump mechanism 18, the hydraulic oil in the oil tank 2 passes through the strainer 27 and the check valves 25 and 26, and the fast-forward oil chamber. 17 is supplied.

An oil passage 28 is provided between the fast-forward oil chamber 17 and the base portion 4a of the cylinder 4, and as shown in FIG. 3, the oil passage 28 is biased by a spring in the valve closing direction. An unload valve 31 equipped with a system 29 and a ball valve 30 is provided on a surface perpendicular to the axial direction of the tool body 1, and the pressure of the working oil in the rapid-feed oil chamber 17 is increased by pressurizing the pump mechanism 18. When the pressure exceeds the set pressure, the valve is opened so that hydraulic oil can be supplied to the base portion 4a of the cylinder 4 via the oil passage 28, and the release stem 32 that abuts the ball valve 30 is provided. As shown in FIG. 4, the ball valve 30 can be forcibly opened by operating the return lever 39 from the outside.

Further, an independent oil passage 33 is provided between the base portion 4 a of the cylinder 4 and the oil tank 2, and a relief valve 34 is provided in the oil passage 33, and the base portion 4 a of the cylinder 4 is provided. When the pressure of the working oil rises above a predetermined pressure, the valve is opened and the working oil is returned to the oil tank 2.

Further, an independent oil passage 35 is provided between the base portion 4 a of the cylinder 4 and the oil tank 2, and a return valve 36 is provided in the oil passage 35 in parallel with the unload valve. I am doing it. As shown in FIG. 5, the return valve 36 has a ball valve 37 biased in the valve opening direction by a spring, one end of which protrudes outside the tool body 1 and a spring biased in the valve opening direction. By pushing a certain release stem 38 to open the valve, the working oil of the base portion 4a of the cylinder 4 can be returned to the oil tank 2 via the oil passage 35.

In the hydraulic tool A, in particular, the release system 32 of the unload valve 31 and the release stem 38 of the return valve 36 can be simultaneously pushed by one return lever 39. By this pushing operation, the unload valve 31 and the return valve 36 can be simultaneously forcedly opened.

An oil passage 40 is provided between the base 4 a of the cylinder 4 and the oil passage 23 of the hydraulic oil suction circuit, and an automatic suction valve 41 is provided in the oil passage 40. That is, when the output piston 6 is fast forwarded, the base portion 4a of the cylinder 4 is prevented from being naturally replenished with hydraulic oil from the oil tank 2 via the oil passage 40 to prevent the base portion 4a from being evacuated. The mechanism 18 is adapted to smoothly pressurize the hydraulic oil.

The hydraulic tool A having the piston rapid feed mechanism of the present invention configured as described above will be described with reference to the hydraulic circuit diagram of FIG. After operating the hydraulic tool A so that the pressure-bonded object 13 is located between the pressure-bonding die 12 and the pressure-bonding punch 9, the pressure handle 21 of the pump mechanism 18 is rocked to move the ram 20. By the action, the hydraulic oil of the oil tank 2 is sucked from the strainer 27 via the oil passage 23 and the check valve 25, and further supplied to the fast-forward oil chamber 17 via the oil passage 24 and the check valve 26. Furthermore, since it is introduced into the bottom portion 14a of the small cylinder 14 via the oil passage 16 of the fast-forwarding piston 15, the output piston 6 is fast-forwarded with a small amount of oil. At this time, the base 4a of the cylinder 4 is replenished with hydraulic oil from the oil tank 2 via the automatic suction valve 41 of the oil passage 40. That is, the crimping punch 9 advances rapidly.

When the crimping punch 9 comes into contact with the object 13 to be crimped and receives a load, the output piston 6 is temporarily stopped. When the pressurizing handle 21 is subsequently swung, the hydraulic pressure of the hydraulic fluid supplied increases rapidly without wasting time. When this hydraulic pressure exceeds a predetermined pressure, the ball valve 30 of the unload valve 31 is pushed by the hydraulic fluid. The hydraulic fluid is supplied to the base portion 4a of the cylinder 4 through the oil passage 28.

Then, the output piston 6 advances further against the load according to the pressure of the hydraulic oil of the base portion 4 a of the cylinder 4 and the bottom portion 14 a of the small cylinder 14, and the crimping die 12 and the crimping punch 12 are pressed. The work of crimping the object to be crimped 13 by 9 is performed. When the pressure working oil reaches a predetermined oil pressure, the relief valve 34 in the oil passage 33 is opened to return a part of the hydraulic oil in the base portion 4a of the cylinder 4 to the oil tank 2 to increase the oil pressure. Is prevented and safety is ensured.

After the above crimping work is completed, by pushing the return lever 29 on the side of the tool body 1 with fingers, as shown in FIGS. 4 and 5, the release stem of the unload valve 31 is released. When 32 and the release stem 38 of the return valve 36 are simultaneously pushed to open the respective ball valves 30 and 37, the hydraulic oil in the bottom portion 14a of the small cylinder 14 is introduced into the base portion 4a of the cylinder 4, Since it is quickly returned to the oil tank 2 by the oil passage 35 together with the hydraulic oil of the base portion 4a of the cylinder 4, the output piston 6 is quickly returned by the urging force of the spring 5, and the pressing punch 9 is retracted, and the output piston 6 is retracted. The crimping object 13 is ready for removal.

Further, in the present invention, since the unload valve 31 and the return valve 36 provided in the hydraulic oil return oil passages 28 and 35 do not require a strong spring unlike the relief valve 34, the return lever 39 Can be operated by a light one-touch operation. Further, since the relief valve 34 is also provided in the independent oil passage 33, wear and damage of the valve seat are reduced, and durability as a hydraulic tool is improved.

[0035]

[Effect of the device]

 As apparent from the above description, according to the present invention, the relief valve between the cylinder and the oil tank and the return valve for the hydraulic oil are provided in different oil passages, and the small cylinder bottom and the cylinder base are provided. The unload valve provided in the oil passage can be opened from the outside by force, and the unload valve and the return valve can be opened simultaneously. There is no bottleneck, and the unloading valve and the return valve are opened by operating the return mechanism such as the return lever with a light one-touch operation, and the hydraulic force at the bottom of the small cylinder and the base of the cylinder are simultaneously released by the biasing force of the spring in the cylinder. Moreover, the output piston can be quickly returned by returning it to the oil tank rapidly, and failure due to wear and damage of the valve seat surface of the relief valve can be reduced.

Therefore, according to the present invention, there is an effect that a hydraulic tool excellent in operability and workability and having good durability can be obtained.

[Brief description of drawings]

FIG. 1 is a side sectional view of a hydraulic tool having a quick return mechanism for a piston according to the present invention.

FIG. 2 is a sectional view taken along line II-II in FIG.

FIG. 3 is a sectional view taken along the line III-III in FIG.

4 is a sectional view taken along line IV-IV in FIG.

5 is a cross-sectional view taken along the line VV of FIG.

FIG. 6 is a hydraulic circuit diagram of the hydraulic tool shown in FIG.

FIG. 7 is a side sectional view of a conventional hydraulic tool.

FIG. 8 is a side sectional view of a main part of another conventional hydraulic tool.

[Explanation of symbols]

 A hydraulic tool 1 tool body 2 oil tank 4 cylinder 4a base 5 spring 6 output piston 14 small cylinder 14a bottom 15 fast-forward piston 16 oil passage 18 pump mechanism 20 ram 21 pressurizing handle 25 check valve 26 check valve 31 unload valve 34 Relief valve 36 Return valve 39 Return lever 41 Automatic suction valve

Claims (1)

[Scope of utility model registration request] 1. An oil tank attached to a base end portion of a tool body, a cylinder formed in a tip end portion of the tool body, and an output piston housed in the cylinder and biased toward the base end side by a spring. A fast-forward piston housed in a small cylinder formed through the oil passage and formed in the output piston; and a return valve provided in the oil passage between the oil tank and the base of the cylinder. An unload valve provided in an oil passage between the bottom of the small cylinder and the base of the cylinder,
A manual hydraulic tool comprising a pump mechanism for sucking the working oil of the oil tank and sending it to the bottom of the small cylinder under pressure, wherein a return mechanism for simultaneously opening the return valve and the unload valve from the outside is provided. At the same time, an oil passage is provided between the oil tank and the base of the cylinder, and a relief valve is provided between the oil tank and the cylinder.